Organic optoelectronic materials, synthesis methods, and applications thereof

Abstract

The present invention belongs to the technical field of organic optoelectronic functional materials, specifically relating to a novel organic optoelectronic material, its synthesis method, and its application. The organic optoelectronic material of the present invention has the following general structural formula: #imgabs0#, where M is an oxygen atom, a sulfur atom, or a selenium atom. It is used as a host material for the light-emitting layer in electroluminescent devices. The product of the present invention has a highly rigid structure, which can effectively suppress the degradation of device efficiency caused by AIE and improve device lifespan. It also ensures a certain degree of interaction between the host material and the light-emitting material, reducing device defects and improving the efficiency of energy transfer between the host and the guest.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic photoelectric functional materials, and specifically relates to a novel organic photoelectric material, a synthesis method and an application thereof. Background Art

[0002] Research on organic electroluminescent (OLED) materials has been extensively conducted in academia and industry, and a large number of high-performance OLED materials have been developed. Third-generation OLED materials generally possess a small singlet-triplet energy level difference (ΔEST). Triplet excitons can be converted to singlet excitons via reverse intersystem crossing (RISC), emitting light. This allows for the simultaneous utilization of both singlet and triplet excitons formed under electrical excitation, resulting in devices with internal quantum efficiencies reaching 100%. Therefore, these materials are considered to be among the most promising OLED materials for future applications. Overall, the future development direction of OLEDs is towards high-efficiency, long-life, and low-cost white light devices and full-color displays. However, the industrialization of this technology still faces many key challenges. Currently, the most commonly used OLED materials that combine deep-blue emission with high efficiency and long life are anthracene- and pyrene-based fluorescent materials. However, in existing literature, these fluorescent materials suffer from low fluorescence quantum efficiencies due to rigidity and planarity issues. Therefore, designing and searching for a stable and efficient compound as a new material for organic electroluminescent devices to overcome the shortcomings that arise in practical applications is the focus and future research and development trend in organic electroluminescent device material research.

[0003] 1,6-dibromo-3,8-diisopropylpyrene, i.e., 1,6-diisopropyl-3,8-dibromopyrene, CAS No. 869340-02-3;

[0004] Currently available organic optoelectronic materials (DPAP-DPPA), its currently known use is as a guest material for the light-emitting layer in organic optoelectronic materials. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an organic photoelectric material and a synthesis method and application thereof.

[0006] In order to solve the above technical problems, the present invention provides an organic photoelectric material having the following general structural formula:

[0007]

[0008] M is an oxygen atom, a sulfur atom or a selenium atom.

[0009] As an improvement of the organic photoelectric material of the present invention, the structural formula is any one of the following:

[0010]

[0011] The present invention also provides a method for synthesizing the above-mentioned organic photoelectric material, comprising the following steps:

[0012] Step 1: Add 1,6-diisopropylpyrene to a reaction kettle, then add organic solvent I and heat to 80±10°C, then add bromination reagent, keep the temperature at 80±10°C for reaction, react for 10±1 hours, cool to room temperature and centrifuge (filter), wash the solid obtained by centrifugation (filtering) with organic solvent II and dry to obtain 1,6-dibromo-3,8-diisopropylpyrene;

[0013] 1,6-diisopropylpyrene: brominating agent = molar ratio of 1:2 to 2.2 (preferably 1:2.1);

[0014] Step 2:

[0015] Under the protection of an inert gas (such as nitrogen), 1,6-dibromo-3,8-diisopropylpyrene, an organic solvent III, a base, phenothiazine and its derivatives, a catalyst, and a ligand are mixed and then heated to 80-130° C. for reaction for 14-20 hours; after the reaction is completed, post-treatment is performed to obtain an organic photoelectric material;

[0016] 1,6-dibromo-3,8-diisopropylpyrene: base = 1: (3 ± 0.1) molar ratio;

[0017] 1,6-dibromo-3,8-diisopropylpyrene: phenothiazine and its derivatives = 1:2.2-2.3 molar ratio;

[0018] 1,6-dibromo-3,8-diisopropylpyrene: catalyst = 1:0.05 molar ratio;

[0019] 1,6-dibromo-3,8-diisopropylpyrene:ligand = 1:0.14-0.15;

[0020] The phenothiazine and its derivatives are any of the following: 3,7-dimethyl-10H-phenothiazine, 3,7-dimethyl-10H-phenoxazine, and 3,7-dimethyl-10H-phenoselenazine.

[0021] As an improvement to the synthesis method of the organic photoelectric material of the present invention:

[0022] The bromination reagent in step 1 is any one of the following: N-bromosuccinimide, 1,3-dibromo-5,5-dimethylhydantoin, dibromoisocyanuric acid, or N-bromoacetamide.

[0023] In step 2:

[0024] The catalyst is any of the following: palladium acetate, cuprous iodide, copper oxide;

[0025] The ligand is any one of the following: L-proline, tri-tert-butylphosphine, triphenylphosphine.

[0026] In step 2:

[0027] The base is any one of the following: potassium carbonate, potassium tert-butoxide, sodium tert-butoxide, potassium hydroxide, and cesium fluoride.

[0028] In step one:

[0029] The organic solvent I is at least one of chlorobenzene, 1,4-dioxane, toluene, xylene, and tetrahydrofuran (one or a combination of two); 100 to 160 mL of the organic solvent I is used for every 0.1 mol of 1,6-diisopropylpyrene;

[0030] Organic solvent II is any of the following: chlorobenzene, toluene, or o-dichlorobenzene;

[0031] In the step 2:

[0032] The organic solvent III is any one of the following: toluene, decahydronaphthalene, dichloroethane, cyclohexane; 100 to 150 mL of the organic solvent III is used for every 0.027 mol of 1,6-dibromo-3,8-diisopropylpyrene.

[0033] As a further improvement of the synthesis method of the organic photoelectric material of the present invention:

[0034] The post-processing in step 2 is:

[0035] After the reaction is completed, the temperature is lowered to room temperature, water is added to quench, and the mixture is allowed to stand for separation. The organic phase is adsorbed on diatomaceous earth, filtered, and the filtrate is collected. The organic solvent in the filtrate is removed, and the resulting material is washed with solvent IV, cooled (to about 0°C), crystallized, centrifuged, and dried to obtain an organic photoelectric material.

[0036] The organic solvent IV is any one of the following: toluene, o-dichlorobenzene, xylene.

[0037] The present invention also provides a use of the organic photoelectric material as a main material of a light-emitting layer in an electroluminescent device.

[0038] The chemical reaction of the present invention is as follows:

[0039]

[0040] In the present invention, the electroluminescent device includes a first electrode; a hole injection layer, which is arranged on the first electrode; a hole transport layer, which is arranged on the electron injection layer; a light-emitting layer, which is arranged on the hole transport layer, and the material used for the light-emitting layer includes a pyrene-based blue light-emitting material; an electron transport layer, which is arranged on the light-emitting layer; and a second electrode, which is arranged on the electron transport layer.

[0041] The first electrode is an anode made of indium tin oxide; the second electrode is a cathode made of lithium fluoride or aluminum. The light-emitting layer also includes 1,3-bis(9H-carbazol-9-yl)benzene; the hole injection layer is made of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene; the electron transport layer is made of 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene; and the hole transport layer is made of N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4'-diamine.

[0042] This invention provides the synthesis and application of a novel organic optoelectronic material. Specifically, a novel organic optoelectronic material constructed from a combination of pyrene, phenothiazine, and their derivatives exhibits novel structure and excellent charge transport properties. This type of molecule possesses a highly rigid structure, which can effectively suppress the effects of AIE (AIE) that reduce device efficiency and improve device lifespan. It also ensures a certain degree of interaction between the host material and the luminescent material, reducing device defects and improving the efficiency of energy transfer between the host and guest.

[0043] The poly-condensed ring conjugated molecules (M1, M2, M3) synthesized by the present invention based on phenothiazine derivatives have the characteristics of novel structure, low cost, simple operation, and easy purification.

[0044] The poly-condensed ring conjugated molecules based on phenothiazine derivatives synthesized in the present invention have good solubility and can be dissolved in most organic solvents, such as chloroform, dichloromethane, tetrahydrofuran and chlorobenzene; have a good spectral absorption range and a suitable electrochemical energy level, and are suitable for use as the main material in organic optoelectronic devices.

[0045] In summary, the present invention discloses an organic photoelectric material for organic light-emitting diodes and a preparation method thereof, which has a specific structure and is obtained by coupling reaction with pyrene as the main core. This type of compound has a fluorescence emission with a short wavelength, and its luminescence spectrum is characterized by a narrow half-maximum width, so that this type of substance has a deep blue fluorescence emission and has high luminous efficiency. The material of the present invention has good luminescent properties, high luminous efficiency, good stability, and the synthesis method is simple, easy to implement, and low cost, and has practicality in the field of organic electroluminescent displays. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0047] Figure 1 This is a structural diagram of the electroluminescent device used in the experiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto:

[0049] 1,6-Diisopropylpyrene, CAS: 110210-53-2.

[0050] Example 1:

[0051] Synthesis of 1,6-dibromo-3,8-diisopropylpyrene

[0052]

[0053] After adding 1,6-diisopropylpyrene (28.6 g, 0.1 mol) to the reactor, 1,4-dioxane (140 mL) was added and the temperature was raised to 80°C. The mixture was stirred until dissolved, and then 1,3-dibromo-5,5-dimethylhydantoin (60.04 g, 0.21 mol, added in three batches. The reaction temperature was controlled not to exceed 80°C during the addition process. The mixture was then kept at 80°C for 10 hours. After the reaction was completed, the temperature was lowered to room temperature (25°C). The reaction solution was transferred to a centrifuge tube and centrifuged (centrifugal speed 3000 r / min) to form an upper centrifuge liquid and a lower solid layer, respectively, which were then separated by suction filtration.

[0054] The solid obtained by filtration was washed with chlorobenzene (300 mL*3 times) and dried to obtain 1,6-dibromo-3,8-diisopropylpyrene (38 g, 0.086 mol). 1 H NMR (400MHz, CDCl3) δ8.03 (s, 2H), 7.70 (dd, 4H), 2.88 (dd, 2H), 1.31 (s, 12H). HRMS(ESI,Positive)(m / z):[M]+Calcd for:C22H20Br2, 441.99, found: 440.27. Elemental Analysis: C, 59.49; H, 4.54; Br, 35.98.

[0055] Example 2: Synthesis of TM1

[0056]

[0057] 1,6-dibromo-3,8-diisopropylpyrene (12 g, 0.027 mol) was added to the reactor, followed by toluene (120 mL), the temperature was raised to 90°C, and stirring was performed until dissolved. Potassium tert-butoxide (9.08 g, 0.081 mol) and 3,7-dimethyl(d6)-10H-phenothiazine (13.86 g, 0.06 mol) were then added. The air in the reactor was replaced with nitrogen three times, and palladium acetate (0.3 g, 0.00135 mol) and L-proline (0.47 g, 0.004 mol) were added. The air was replaced with nitrogen three times, and the reaction was kept at 100°C until the reaction was complete (TLC monitoring showed that the reaction was complete when there were only two color points, and the reaction time was about 14 hours).

[0058] After the reaction is completed, the temperature is lowered to room temperature, water (200 mL) is added to quench the reaction, and the mixture is allowed to stand to separate the organic phase (toluene phase) and the aqueous phase. Celite (20 g) is added to the organic phase and mixed, which is then filtered and the filtrate (toluene phase) is collected. The toluene in the filtrate is removed to obtain a solid. The obtained solid is dissolved in xylene (100 mL) and cooled to 0°C to crystallize. The crystallized material is centrifuged. After centrifugation (speed 3000 r / min), the lower wet solid is dried (dried to constant weight at 50°C) to obtain TM1.

[0059] 1 H NMR(400MHz, CDCl3)δ7.70(d,4H),7.64(s,2H),7.15(d,4H),6.79(s,4H),

[0060] 6.87(d,4H),2.88(m,2H),1.33(d,12H). HRMS(ESI,Positive)(m / z):[M] + Calcdfor:

[0061] C50H32D12N2S2, 749.11, found: 748.63. Elemental Analysis: C, 80.17; H, 7.53; N, 3.74; S, 8.56.

[0062] Example 3: Synthesis of TM2

[0063]

[0064] Add 1,6-dibromo-3,8-diisopropylpyrene (12 g, 0.027 mol) to the reactor, and then add decahydronaphthalene.

[0065] (100mL) was heated to 100 ° C and stirred until dissolved, followed by the addition of sodium tert-butoxide (7.77 g, 0.081 mol) and 3,7-dimethyl (d6) -10H- phenoxazine (13.04 g, 0.06 mol). The air in the reactor was replaced three times with nitrogen, and then cuprous iodide (0.25 g, 0.00135 mol) and L-proline (0.47 g, 0.004 mol) were added. The air was replaced three times with nitrogen, and the reaction was kept at 120 ° C until the reaction was complete (about 16 hours).

[0066] After the reaction was completed, the temperature was cooled to room temperature, and water (200 mL) was added to quench the reaction. The mixture was allowed to stand to separate the organic phase (decalin phase) and the aqueous phase. Celite (20 g) was added to the organic phase and mixed. The mixture was then filtered, and the filtrate (decalin phase) was collected. The decalin in the filtrate was removed to obtain a solid. The obtained solid was dissolved in toluene (100 mL) and the temperature was lowered to 0°C for crystallization. The crystallized material was centrifuged (at a speed of 3000 r / min) and the lower wet solid was dried to obtain TM2.

[0067] 1 H NMR(400MHz, CDCl3)δ7.69(d,4H),7.64(s,2H),7.09(d,4H),6.85-6.84(m,8H),

[0068] 2.88(m,2H),1.31(d,12H). HRMS(ESI,Positive)(m / z):[M] + Calcd for:C50H32D12N2O2,

[0069] 716.98, found: 716.04. Elemental Analysis: C, 83.76; H, 7.87; N, 3.91; O, 4.46.

[0070] Example 4: Synthesis of TM3

[0071]

[0072] 1,6-dibromo-3,8-diisopropylpyrene (12 g, 0.027 mol) was added to the reactor, followed by cyclohexane (150 mL) and the temperature was raised to 90 ° C. Stirring until dissolved, followed by the addition of cesium fluoride (12.31 g, 0.081 mol) and 3,7-dimethyl (d6) -10H- pheneselenoazine (16.8 g, 0.06 mol). The air in the reactor was replaced three times with nitrogen, followed by the addition of palladium acetate (0.3 g, 0.00135 mol) and tri-tert-butylphosphine (0.808 g, 0.004 mol), and then replaced with nitrogen three times. The reaction was kept at 80 ° C until the reaction was complete (about 19 hours).

[0073] After the reaction was completed, the temperature was cooled to room temperature and water (200 mL) was added to quench the reaction. The mixture was allowed to stand to separate the organic phase (cyclohexane phase) and the aqueous phase. Celite (25 g) was added to the organic phase and mixed. The mixture was then filtered and the filtrate (cyclohexane phase) was collected. The cyclohexane in the filtrate was removed to obtain a solid. The obtained solid was dissolved in o-dichlorobenzene (120 mL) as a solvent and then cooled to 0°C to crystallize. The crystallized material was centrifuged (at a speed of 3000 r / min) and the lower wet solid was dried to obtain TM3.

[0074] 1 H NMR (400MHz, CDCl3) δ7.70(d,4H),7.64(s,2H),7.17(s,4H),7.13-7.12(m,8H),2.88(m,2H),1.31(d,12H). HRMS(ESI,Positive)(m / z):[M] + Calcd for:C50H32D12N2Se2, 844.26, found: 844.26. Elemental Analysis: C, C, 71.25; H, 6.69; N, 3.32; Se, 18.74.

[0075] The electrochemical energy levels and other parameters of the compounds TM1 to TM3 obtained in Examples 1 to 3 were measured (including the absorption peaks and electrochemical energy levels of TM1, TM2, and TM3). The results are shown in Table 1 below:

[0076] Table 1

[0077]

[0078]

[0079] Experiment 1: To verify whether the properties of the novel organic optoelectronic material of the present invention meet the requirements of electroluminescent devices, the target products TM1, TM2, and TM3 obtained in this example were used to prepare devices and perform performance tests.

[0080] like Figure 1 As shown, the present invention also provides an electroluminescent device (refer to the published patent CN106831745 A).

[0081] Specifically, the electroluminescent device includes a first electrode 1, a hole injection layer 2, a hole transport layer 3, a light-emitting layer 4, an electron transport layer 5, and a second electrode 6. The hole injection layer 2 is disposed on the first electrode 1; the hole transport layer 3 is disposed on the electron injection layer 2; the light-emitting layer 4 is disposed on the hole transport layer 3, and the materials used in the light-emitting layer 4 include a host material and a guest material (weight ratio of 90:10), wherein the host material is the organic photoelectric material described in the present invention and 1,3-dicarbazol-9-ylbenzene (weight ratio of 1:4), and the guest material is 9,9-dimethyl-10-phenylacridine. The organic photoelectric material described in the present invention serves as the host material of the light-emitting layer and contains a blue light-emitting material; the electron transport layer 5 is disposed on the light-emitting layer 4; and the second electrode 6 is disposed on the electron transport layer 5.

[0082] In this experiment, the first electrode 1 is an anode made of indium tin oxide; the second electrode 6 is a cathode made of lithium fluoride or aluminum. The electron transport layer 5 is made of 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene; the hole transport layer 3 is made of N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4'-diamine; and the hole injection layer 2 is made of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene.

[0083] The electroluminescent devices prepared above were tested according to the method described in CN 106831745 A. The performance data of the electroluminescent devices of target compounds TM1, TM2, and TM3 are shown in Table 2 below.

[0084] Table 2

[0085]

[0086] The electroluminescent device of the present invention adopts organic luminescent materials in the luminescent layer, effectively manufactures the electroluminescent device, and improves the luminous efficiency of the electroluminescent device.

[0087] Comparative Experiment 1: The existing organic photoelectric material DPAP-DPPA disclosed in the background art was tested according to the method described in the above experiment. The results are shown in Table 3. It can be seen that its lifespan performance is not as good as that of the present invention.

[0088] Table 3

[0089]

[0090] Comparative Experiment 2: Another organic photoelectric material obtained in the process of the present invention, whose structural formula is

[0091] The test was carried out according to the method described in the above experiment, and the results were shown in Table 4. Therefore, it can be seen that its life performance is not as good as that of the present invention.

[0092] Table 4

[0093]

[0094] Experiment 2: The fluorescence quantum efficiency stability of TM1, TM2, TM3 of the present invention, DPAP-DPPA of Comparative Experiment 1, and the organic photoelectric materials of Comparative Experiment 2 were tested according to conventional methods. The results are shown in Table 5 below.

[0095] Table 5

[0096] Compound TM1 TM2 TM3 Comparative Experiment 1 Comparative Experiment 2 Fluorescence quantum efficiency (Ψ) 67 65 60 53 42

[0097] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples and is subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention are considered to be within the scope of protection of the present invention.

Claims

1. An organic photoelectric material, characterized in that: It has the following general structural formula: ； M is an oxygen atom, a sulfur atom or a selenium atom.

2. The organic photoelectric material according to claim 1, characterized in that The structural formula is any of the following: 、 、 。 3. The method for synthesizing the organic photoelectric material according to claim 1 or 2, characterized in that The steps include: Step 1: Add 1,6-diisopropylpyrene and organic solvent I to a reactor, then heat to 80±10°C, then add a bromination reagent, keep the temperature at 80±10°C, react for 10±1 hours, cool to room temperature, and centrifuge. Wash the solid obtained by centrifugation with organic solvent II and then dry to obtain 1,6-dibromo-3,8-diisopropylpyrene; 1,6-diisopropylpyrene: bromination reagent = 1:2~2.2 molar ratio; The bromination reagent is any of the following: N-bromosuccinimide, 1,3-dibromo-5,5-dimethylhydantoin; Step 2: Under the protection of inert gas, 1,6-dibromo-3,8-diisopropylpyrene, organic solvent III, base, phenothiazine and its derivatives, catalyst and ligand are mixed and then heated to 80-130°C for reaction for 14-20 hours; after the reaction is completed, post-treatment is performed to obtain an organic optoelectronic material; 1,6-dibromo-3,8-diisopropylpyrene: base = 1: (3 ± 0.1) molar ratio; 1,6-dibromo-3,8-diisopropylpyrene: phenothiazine and its derivatives = 1:2.2~2.3 molar ratio; 1,6-dibromo-3,8-diisopropylpyrene: catalyst = 1:0.05 molar ratio; 1,6-dibromo-3,8-diisopropylpyrene:ligand = 1:0.14~0.15; The catalyst is any of the following: palladium acetate, cuprous iodide; The ligand is any of the following: L-proline, tri-tert-butylphosphine, triphenylphosphine; Phenothiazine and its derivatives are any of the following: 、 、 。 4. The method for synthesizing the organic photoelectric material according to claim 3, characterized in that In the step 2: The base is any one of the following: potassium carbonate, potassium tert-butoxide, sodium tert-butoxide, potassium hydroxide, and cesium fluoride.

5. The method for synthesizing an organic photoelectric material according to claim 4, wherein: In the step 1: The organic solvent I is at least one of chlorobenzene, 1,4-dioxane, toluene, xylene, and tetrahydrofuran; 100-160 mL of the organic solvent I is used for every 0.1 mol of 1,6-diisopropylpyrene; Organic solvent II is any of the following: chlorobenzene, toluene, or o-dichlorobenzene; In the step 2: The organic solvent III is any one of the following: toluene, decahydronaphthalene, dichloroethane, cyclohexane; 100-150 mL of the organic solvent III is used for every 0.027 mol of 1,6-dibromo-3,8-diisopropylpyrene.

6. The method for synthesizing an organic photoelectric material according to any one of claims 3 to 5, characterized in that The post-processing in step 2 is as follows: After the reaction is completed, the mixture is cooled to room temperature, quenched with water, and allowed to stand for separation. The organic phase is adsorbed on diatomaceous earth, filtered, and the filtrate is collected. The organic solvent in the filtrate is removed, and the resulting material is washed with solvent IV, cooled, crystallized, centrifuged, and dried to obtain an organic photoelectric material. The organic solvent IV is any one of the following: toluene, o-dichlorobenzene, xylene.

7. The use of the organic photoelectric material according to claim 1 or 2, characterized in that: As the main material of the light-emitting layer in electroluminescent devices.

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